Human

HumanComparable

package Human;

public class HumanComparable implements Comparable{
	private int age;
	
	public HumanComparable (int age){
		this.age= age;
	}
	
	public int getAge(){
		return age;
	}
	
	@Override
	 public int compareTo (Object another ){
		HumanComparable h = (HumanComparable)another;
		
		if(age<h.getAge())
			return -1;
		if(age>h.getAge())
			return 1;
		else return 0;
		
	}

}

Myclass

package Human;

import java.util.Arrays;

public class Myclass {
		public static void main(String[] args) {
			HumanComparable[] list = { new HumanComparable(40), new HumanComparable(20), new HumanComparable(3), new HumanComparable(7) };
			Arrays.sort(list);
			
			System.out.println(list.length + "----------------- " );
			
			HumanComparable[] list1 = new HumanComparable[list.length];
			for(int i = list.length-1, j = 0; i >= 0; i--, j++){
				list1[j]=list[i];
			}
			
			list = list1;
			
			for (HumanComparable h : list)
				System.out.println(h.getAge());
		}
	

}